Open Validation Server is a free online service for validating IGC files, used by the FAI CIVL World XC Online Contest and many other national and international flying contests.

IGC files are required to include a special file signature, which can be validated later by using a program provided by the instrument manufacturer or software author. This service makes use of these programs to check that IGC file data has not been altered.
The IGC file format has been developed by members of the FAI IGC (gliding commission) in December 1994. The old draft specification is available as a PDF download here. Please note, the old draft is (as the name would say really old.) Please use latest IGC spec and CIVL draft for your development. The draft is intended to facilitate the introduction of GPS technology into IGC gliding and gliding competition verification, to create a standard for IGC-Approved Flight Recorders (GNSS).

The Open Validation Server project started in 2003 for the HG/PG Onlinecontest at Segelflugszene. (www.onlinecontest.org) The main goal was, to allow the use of IGC files on onlinecontest systems without the need to buy expensive GNSS loggers at hanggliding / paragliding szene.

The Open Validation Server is free to use for any onlinecontest who will find it useful but without warranty.

At FAI CIVL World Online Contest level (WXC) we approve Software by testing it against minimum requirements to ensure stability for Servers and Pilot client PC software. A 3-letter code starting with X character is assigned to the software, outside from FAI GNSS logger approval process.

Special thanks to John Stevenson(UK), Marcin Kostur(PL), Hans Trautenberg(DE), Christian Hynek(AT), Andreas Rieck(DE) for the great help on this project.


  • latest FAI IGC Technical Specification (bottom of the target page) - link
  • CIVL IGC vali specification changes - draft


The Fédération Aéronautique Internationale (FAI) is the World Air Sports Federation and was founded in 1905. It is a non-governmental and non-profit making international organisation with the basic aim of furthering aeronautical and astronautical activities worldwide, ratifying world and continental records and coordinating the organization of international competitions.

The FAI Hang Gliding and Paragliding Commission of the FAI (CIVL) conducts FAI's hang gliding and paragliding activities in particular World Records and International Competitions.

The FAI Gliding Commission (IGC) conducts FAI's gliding activities (sailplane) in particular World Records and International Competitions with the exception of glider aerobatics.